In a materials handling facility, such as an order fulfilment center, multiple customer orders are received, where each order specifies one or more items from inventory to be shipped to the customer that submitted the order. To fulfill the customer orders, the one or more items specified in each order may be retrieved, or picked, from inventory (which may also be referred to as stock storage) in the materials handling facility. Under direction of a control system, picked items may be singulated and then inducted into a conveyance mechanism that routes the items to particular destinations, such as sorting stations, in accordance with the customer orders currently being processed. From the sorting station, the items can be directed to an order processing station, such as a packing station at which one or more units of items for an order are processed, packed, and labeled for shipping to the customer. A picked, packed and shipped order does not necessarily include all of the items ordered by the customer, as an outgoing shipment to a customer may include only a subset of the ordered items available to ship at one time from the materials handling facility.